Contributing

Contributions are always welcome, no matter how large or small!

We want this community to be friendly and respectful to each other. Please follow it in all your interactions with the project. Before contributing, please read the code of conduct.

Development workflow

This project is a monorepo managed using Yarn workspaces. It contains the following packages:

• The library package in the root directory.
• An example app in the example/ directory.
• This documentation website in the website/ directory (yarn docs:start for local development, yarn docs:build to build).

To get started with the project, run yarn in the root directory to install the required dependencies for each package:

yarn

Since the project relies on Yarn workspaces, you cannot use npm for development.

The example app demonstrates usage of the library. You need to run it to test any changes you make.

It is configured to use the local version of the library, so any changes you make to the library's source code will be reflected in the example app. Changes to the library's JavaScript code will be reflected in the example app without a rebuild, but native code changes will require a rebuild of the example app.

The example app is an Expo app using Continuous Native Generation: the example/ios and example/android directories are generated by expo prebuild and are not committed to git. Native project configuration (bundle id, permissions, NSFaceIDUsageDescription, architecture flags) lives in example/app.json. Running yarn example ios or yarn example android generates the native directories automatically on first run; you can also generate them explicitly with yarn example expo prebuild. For iOS, prebuild runs pod install itself, but CocoaPods must be installed on your machine (pod on your PATH).

If you want to use Android Studio or XCode to edit the native code, first run a prebuild (or a normal yarn example ios/yarn example android), then open the generated projects: for Objective-C or Swift, open example/ios/ReactNativeBiometricsExample.xcworkspace in XCode and find the source files at Pods > Development Pods > @sbaiahmed1/react-native-biometrics.

To edit the Java or Kotlin files, open example/android in Android studio and find the source files at sbaiahmed1-react-native-biometrics under Android. Remember that these directories are generated — persistent native-project changes belong in example/app.json (or the library's own android//ios/ folders), not in the generated projects.

You can use various commands from the root directory to work with the project.

To start the packager:

yarn example start

To run the example app on Android:

yarn example android

To run the example app on iOS:

yarn example ios

By default the example runs the new architecture on iOS and the old architecture on Android. This covers both JS event-emitter paths, but on the Android native side only android/src/oldarch is built — android/src/newarch is not exercised by the default configuration. To validate it, set android.newArchEnabled to true in example/app.json (the same works in reverse for ios.newArchEnabled), then regenerate and rebuild that platform:

yarn example expo prebuild --clean --platform android   # or ios
yarn example android                                    # or ios

To confirm which architecture the app is running, check the Metro logs for a message like this:

Running "main" with {"fabric":true,"initialProps":{"concurrentRoot":true},"rootTag":1}

"fabric":true means the new architecture; on Android you should see "fabric":false (old architecture).

Make sure your code passes TypeScript and ESLint. Run the following to verify:

yarn typecheck
yarn lint

To fix formatting errors, run the following:

yarn lint --fix

Remember to add tests for your change if possible. Run the unit tests by:

yarn test

Commit message convention

We follow the conventional commits specification for our commit messages:

• fix: bug fixes, e.g. fix crash due to deprecated method.
• feat: new features, e.g. add new method to the module.
• refactor: code refactor, e.g. migrate from class components to hooks.
• docs: changes to documentation, e.g. add usage example for the module.
• test: adding or updating tests, e.g. add integration tests using detox.
• chore: tooling changes, e.g. change CI config.

Our pre-commit hooks verify that your commit message matches this format when committing.

Linting and tests

ESLint, Prettier, TypeScript

We use TypeScript for type checking, ESLint with Prettier for linting and formatting the code, and Jest for testing.

Our pre-commit hooks verify that the linter and tests pass when committing.

Publishing to npm

We use release-it to make it easier to publish new versions. It handles common tasks like bumping version based on semver, creating tags and releases etc.

To publish new versions, run the following:

yarn release

Scripts

The package.json file contains various scripts for common tasks:

• yarn: setup project by installing dependencies.
• yarn typecheck: type-check files with TypeScript.
• yarn lint: lint files with ESLint.
• yarn test: run unit tests with Jest.
• yarn example start: start the Metro server for the example app.
• yarn example android: run the example app on Android.
• yarn example ios: run the example app on iOS.

Sending a pull request

Working on your first pull request? You can learn how from this free series: How to Contribute to an Open Source Project on GitHub.

When you're sending a pull request:

• Prefer small pull requests focused on one change.
• Verify that linters and tests are passing.
• Review the documentation to make sure it looks good.
• Follow the pull request template when opening a pull request.
• For pull requests that change the API or implementation, discuss with maintainers first by opening an issue.

Guidelines

• 🐛 Bug Reports: Include device info, OS version, and reproduction steps
• ✨ Feature Requests: Describe the use case and expected behavior
• 🔧 Pull Requests:
  • Follow existing code style
  • Add tests for new features
  • Update documentation
  • Test on both iOS and Android

Code Style

• Use TypeScript for type safety
• Follow existing naming conventions
• Add JSDoc comments for public APIs
• Ensure debug logging for new methods